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Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles

  • Based on 10,832 reviews
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Style: Receptacle Tester


Features

  • CLEAR LCD READOUT: GFCI Receptacle Tester features a large backlit LCD readout for easy voltage reading and clear indication of wiring conditions
  • TRIP TIME DISPLAY: LCD readout shows the time required to trip a GFCI device, allowing for quick and accurate troubleshooting
  • DETECT COMMON WIRING FAULTS: Detect and identify common wiring faults, ensuring electrical safety and proper functionality of GFCI receptacles
  • PATENT-PENDING OPEN NEUTRAL & OPEN GROUND DETECTION: Innovative detection system identifies Open Neutral and Open Ground wiring faults, enhancing safety measures
  • CONVENIENT AUTO-HOLD FEATURE: Auto-Hold function holds the reading for hard-to-reach outlets, providing convenience and ease of use
  • VISIBLE LED INDICATORS: Bright green and red LEDs illuminate to provide clear visual indicators of wiring conditions, making it easy to identify issues
  • CAT II 135V SAFETY RATING: GFCI Receptacle Tester has a CAT II 135V safety rating, ensuring reliable and safe electrical testing for various applications

Description

The RT250 is an electrical receptacle tester that tests the wiring conditions at an electrical outlet and inspects GFCI devices. The LCD displays the voltage, identifies the wiring fault, and the time required to trip a GFCI device. It is designated for use with North American 3-wire 120V electrical outlets. For more than 160 years, Klein Tools has manufactured premium- quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.

Specs & Other Info

Specification Details
Brand Klein Tools
Energy Type Operates on Batteries
Design Receptacle Tester
Color Scheme Combination of Green and Red
Weight Lightweight at 4.16 Ounces
Manufacturer Continuation Continuous production, not Discontinued
Dimensions Compact size, 4.53 x 1.16 x 2 inches and 4.16 Ounces
Model Number Designated as RT250
Target Audience Applicable for both Men and Women
Batteries Requires 2 AAAA batteries (provided)
Available Since First introduced on December 17, 2020
Manufacturer Produced by Klein Tools
Made In Originates from China
Selling Rank #1,598 in Tools & Home Improvement, #3 in Circuit Testers

Frequently asked questions

The Klein Tools RT250 is an electrical testing tool, specifically designed to test standard 3-wire 120V electrical receptacles. It can measure the voltage and indicate whether the GFCI (Ground Fault Circuit Interrupter) is properly functioning. This would be helpful in preventing electric shocks.

The LCD display on the RT250 is an essential feature that provides a clear digital presentation of the voltage present in the outlet. The LCD display is also used to explain the wiring condition symbols that might appear on the device. It is designed to make testing more accurate and easy.

The Klein Tools RT250 Outlet Tester comes in two colors, red and green, to provide an easy and clear indication of the status of the electrical receptacle. Green indicates that the outlet is properly wired, while red signals that there is a problem with the wiring.

The Klein Tools RT250 Outlet Tester provides an essential service in preventing electrical shocks. By testing whether the GFCI of an outlet is properly functioning, the device ensures that dangerous electrical faults are detected immediately. This allows for early intervention and prevention of potential harm.

Top Amazon Reviews

🚀 Abunda's Overview

This is our summary and key points to consider based on customer reviews.


The product under review appears to be an exceptionally reliable and effective tool for electrical testing. It piques a high degree of satisfaction among users who have employed it for various tasks such as installing GFI plugs, testing power supplies, and verifying proper outlet wiring. Its distinct feature seems to be its voltage readout, which users particularly admire and find superior to other similar products. Despite its excellent rating, one user pointed out a minor inconvinience with the display positioning.

Pros

  • 👍 Highly effective for a range of electrical tasks.
  • 👍 Voltage readout feature is superior to other market options.
  • 👍 Potentially saves significant money by preventing electrical mishaps.
  • 👍 Easy to use and convenient to carry around.

Cons

  • 👎 The display may be inconveniently positioned for some installations.

Should I Buy It?

If you're in need of a reliable, user-friendly, and effective tool for various electrical tasks, this product comes highly recommended by multiple users. Its ability to provide voltage readout sets it apart, and it's been praised for its potential to save significant money by preventing electrical mishaps. Despite one minor issue with the display positioning, the overwhelmingly positive feedback suggests this product could be a valuable addition to your toolkit.


  • A must have
Style: Receptacle Tester
Great outlet tester, it is easy to use and fits anywhere on my pouch. It is sturdy incase you drop it. It is accurate and fast.
Reviewed in the United States on September 20, 2025 by Javier Garcia

  • Reliable, safe, and easy-to-use electrical tester
Style: Receptacle Tester
This outlet tester gives me a lot of peace of mind when working around the house. It’s simple to use—just plug it in, and the bright LCD display gives clear, easy-to-read results. The color-coded indicators and built-in GFCI test function make it incredibly functional for quickly checking outlets and ensuring wiring is safe. It’s also reassuring to know I’m catching potential issues before they become bigger problems. The build quality feels solid and durable, so I don’t worry about it failing when I need it most. It works well every time I’ve tested it, even compared to a more expensive professional tester. This is a perfect tool for homeowners or DIYers looking for something safe, accurate, and functional to check their electrical systems. ... show more
Reviewed in the United States on July 22, 2025 by ChrisFromTexas ChrisFromTexas

  • Industry standard for a good reason
Style: Receptacle Tester
no wonder it is the industry standard. Works wonderfully and provides everything one needs to test GCFI outlets. Basic stuff for your tool chest.
Reviewed in the United States on August 16, 2025 by Whodiini

  • Industry standard for a reason -- accurate, pocket size and quick to read
Style: Receptacle Tester
This is an industry standard. I've had a lot of electrical work done on my place and was very pleased to see the journeyman electrician had one of these. He sang its praises for being inexpensive, essential for electrical household safety, super bright, fits just right in the hand (or small pocket), and the design is well-labeled and so easily read with the LCD screen. I was quite happy I bought it after hearing all that!!! Great for finding and fixing open ground and so many other issues. Put one in your electrical kit and stay safe!! ... show more
Reviewed in the United States on May 9, 2025 by jkbMN

  • Decent product
Style: Receptacle Tester
Voltage reads 2V high. Other than that -- OK.
Reviewed in the United States on September 11, 2025 by AmazonRick

  • Easy use and operation
Style: Receptacle Tester
Works great. Plug it into an electrical socket and it tells you if it’s wired correctly. Easy to use and operate.
Reviewed in the United States on September 25, 2025 by npmpike

  • A little more expensive than the simple testers but worth it
Style: Receptacle Tester
I have one of those 3 LED testers already, the ones with the 2 yellow and one red light... and has a legend on it so that you can tell what is what. Works great... only issue is that when I was working outdoors or in a brightly lit room, it wasn't so obvious which LED were lit. So I bought the Klein as it wasn't a bad price and had the built in GFCI too. My old set, I had a separate GFCI tester which also worked great but just meant I had 2 separate testers. I played with the Klein soon as I got it having installed the batteries (Klein supplied I might add!!!!). You need to hold the power button down a couple of seconds and then the LCD comes alive. I tried it in various outlets around the house and found it to be a really effective device. The unit has only 2 LED's and there's no mistaking when they light up, both bright... A green one which clearly means OK and a red one meaning a fault in the wiring has been detected. I already had a purpose made miswired test lead I used for verifying the fault detection capability. Works great. I also like that it provides a reading of the actual voltage detected. It's not just a passive device. I have only one minor concern... When I put this in my toolbox I'm worried about something resting on the power switch and running the batteries down, so for now, having already carefully cut around the edge of the packaging, I'm keeping it in the packaged plastic. Might be overkill and maybe I'll buy a protective case for it if I feel inclined but for now, perfectly happy with the device and definitely recommend over the typical passive receptacle testers, even though they may be half the price. ... show more
Reviewed in the United States on June 16, 2025 by Stephen Johnston

  • This is a must have.
Style: Receptacle Tester
This is a nice tool. Iused to test GFIC plugs and I like that it shows the voltage. The extra cost is worth it. To get GFIC tester volt meter.
Reviewed in the United States on October 3, 2025 by JQ

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